$ { \left[\begin{array}{rr}{-1} & {1} \\ {0} & {-1}\end{array}\right]+\left[\begin{array}{rr}{-2} & {3} \\ {-2} & {4}\end{array}\right] = {?} } $
Solution: To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{-1}+{-2} & {1}+{3} \\ {0}+{-2} & {-1}+{4}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-3} & {4} \\ {-2} & {3}\end{array}\right]}$